v2.0.0.1

Publisium

54 lines · 1.7 KB

<?php
declare(strict_types=1);
require_once __DIR__ . '/slugger.php';
final class TableOfContents
{
public static function build(string $html): array
{
$items = [];
$usedIds = [];
$processed = preg_replace_callback('#<h([23])>(.*?)</h\1>#s', static function (array $match) use (&$items, &$usedIds): string {
$level = (int) $match[1];
$label = trim(html_entity_decode(strip_tags($match[2]), ENT_QUOTES | ENT_HTML5, 'UTF-8'));
if ($label === '') {
return $match[0];
}
$base = Slugger::make($label);
$base = $base !== '' ? $base : 'section';
$id = 'toc-' . $base;
$suffix = 2;
while (isset($usedIds[$id])) {
$id = 'toc-' . $base . '-' . $suffix;
$suffix++;
}
$usedIds[$id] = true;
$items[] = ['id' => $id, 'label' => $label, 'level' => $level];
return '<h' . $level . ' id="' . $id . '">' . $match[2] . '</h' . $level . '>';
}, $html);
return [$processed ?? $html, $items];
}
public static function render(array $items): string
{
if (count($items) < 2) {
return '';
}
$html = '<details class="article-toc" open><summary>' . htmlspecialchars(Language::get('article_toc_title', 'Table of contents')) . '</summary><ul class="article-toc-list">';
foreach ($items as $item) {
$html .= '<li class="article-toc-item article-toc-level-' . (int) $item['level'] . '"><a href="#' . htmlspecialchars($item['id'], ENT_QUOTES) . '">' . htmlspecialchars($item['label']) . '</a></li>';
}
return $html . '</ul></details>';
}
}